Actually, there are a couple of them who could deserve a revamp (and a couple of slightly successful attempts were made in past).
The ones which come to my mind are Master Jailer (the Johns version wasn't that bad), Neutron, Black Zero, Atomic Skull and Amalak. Back in the days I had a soft spot for Amalak in particular, especially the Pasko version.
I vaguely remember that Kurt Busiek was interested in a revamp of the Atomic Skull in his run and wanted to elevate him to an A-list villain for a while. But as far as I know, it never happened.